This invention relates to a joint connector and a method of producing the joint connector.
There is known a joint connector of the type in which a bus bar structure is attached to a housing having a plurality of juxtaposed metal terminals received therein. The bus bar structure comprises a holder body, made of a synthetic resin, and a plurality of bus bars made of metal, and each of the bus bars has a plurality of tabs. The tabs are divided into a plurality of groups, and the group of tabs for each bus bar are electrically connected to each other. When the bus bar structure is attached to the housing, the tabs contact the associated metal terminals, respectively, so that the plurality of metal terminals are short-circuited in a predetermined pattern. One such joint connector is disclosed in the Unexamined Japanese Patent Application Publication No. Hei 4-32175.
Even in the case where there are a plurality of short-circuiting patterns, the bus bar structure includes the bus bar-forming part of a common design so that the number of the component parts can be reduced. More specifically, as shown in FIG. 9, a bus bar base member 102, having a plurality of juxtaposed tabs 104 extending from a side edge of a strip-like interconnecting portion 103, is integrally joined to a tubular holder body 101 by insert molding, thereby producing a bus bar structure 100 of a common design. Then, the interconnecting portion 103 of the bus bar structure 100 is severed at a portion thereof, thereby dividing the bus bar base member 102 into a plurality of bus bars corresponding to a predetermined short-circuiting pattern.
A plurality of upwardly and downwardly-open, punching grooves 105 are formed in the holder body 101, and that portion of the interconnecting portion 103, disposed between any two adjacent tabs 104, is exposed through the corresponding punching groove 105. For severing the connecting portion 103, a die 106 is held against the lower surface of the interconnecting portion 103 at the predetermined punching groove 105, and a punch 107 is driven from the upper side, as shown in FIG. 10.
The die 106 has a pair of guide walls 106A for fitting into the punching groove 105 from the lower side, and the punch 107 has a projecting piece-shape so as to be inserted between the two guide walls 106A. In the severing operation, the distal ends of the guide walls 106A are held against the lower surface of the interconnecting portion 103, and in this condition the punch 107 is driven to punch part (a portion) of the interconnecting portion, and this removed piece is received in the gap between the two guide walls 106A.
In the above joint connector, any two adjacent punching grooves 105 are separated from each other by a partition wall 108, and therefore the guide walls 106A must be formed on the die 106 so as to extend a long the opposed partition walls 108, respectively. The smaller the width of the punching grooves 105, the smaller the thickness of the guide walls 106A, and the smaller the pitch of the tabs 104 (that is, the pitch of the metal terminals), the smaller the width of the punching grooves 105. However, recently, it has been desired to achieve a compact design of the joint connector, that is, to reduce the pitch of the metal terminals, and in order to meet this requirement, the width of the punching grooves 105 must be reduced, and in this connection, the thickness of the guide walls 106A must also be reduced. However, this invites a problem that the strength of the guide walls 106A is reduced.
It is provided with a joint connector of the type in which a bus bar structure is attached to a housing having a plurality of juxtaposed metal terminals received therein. The bus bar structure comprises a holder body, made of a synthetic resin, and a plurality of bus bars made of metal, and each of the bus bars has a plurality of tabs. The tabs are divided into a plurality of groups, and the group of tabs for each bus bar are electrically connected to each other. When the bus bar structure is attached to the housing, the tabs contact the associated metal terminals, respectively, so that the plurality of metal terminals are short-circuited in a predetermined pattern.
Even in the case where there are a plurality of short-circuiting patterns, the bus bar structure includes the bus bar-forming part of a common design so that the number of the component parts can be reduced. More specifically, as shown in FIG. 16, a bus bar base member 202, having a plurality of juxtaposed tabs 202B extending from a side edge of a strip-like interconnecting portion 202A, is integrally joined to a tubular holder body 201 by insert molding, thereby producing a bus bar structure 200 of a common design. Then, the interconnecting portion 202A of the bus bar structure 200 is severed at a portion 202C thereof, thereby dividing the bus bar base member 202 into a plurality of bus bars 203 corresponding to a predetermined short-circuiting pattern.
A plurality of punching holes 204 are formed in the holder body 201, and each punching hole 204 is disposed in registry with that portion of the interconnecting portion 202A disposed between the adjacent tabs 202B. The interconnecting portion 202A can be severed at the punching hole 204, using a die and a punch (not shown). With respect to the severed portion of the interconnecting portion 202A, the bus bar 203 serves to short-circuit a plurality of metal terminals (not shown), and it is clear from this that the interconnecting portion 202A is not severed at that portion thereof disposed between each endmost tab 202B (disposed at each end of the bus bar base member) and the adjoining tab 202B. Therefore, the punching hole 204 is not formed at those regions corresponding respectively to the opposite end portions of the bus bar base member 202, and the opposite end portions of the interconnecting portion 202A are embedded in the resin-molded holder body 201.
The punching holes 204 are formed by removing part of a mold (which holds the bus bar base member 202) in the insert molding operation. Therefore, the formation of the punching holes 204 is significant since this facilitates the severing of the interconnecting portion 202A, and besides can provide the regions where the bus bar base member 202 is held during the inserting molding. Therefore, in the case of the above construction in which any punching hole 204 is not formed in the opposite end portions, the end portions of the interconnecting portion 202A are deformed by an injection pressure during the molding operation, which leads to a possibility that the alignment of the tabs 202B, disposed respectively at the opposite end portions, are adversely affected.
A joint connector comprises a housing, having a plurality of juxtaposed metal terminals received therein, and a bus bar structure, which includes an electrically-conductive bus bar, having a plurality of juxtaposed tabs extending from a side edge of an interconnecting portion, and a holder body of a synthetic resin integrally joined to the busbar. When the busbar structure is attached to the housing, the tabs contact the associated metal terminals, respectively, so that the metal terminals are short-circuited in a predetermined pattern.
There is known a method of producing a bus bar structure for this kind of joint connector, in which a chain terminal structure, having a plurality of bus bars connected to side edges of a carrier through bridge portions, is first formed by pressing, and then the bus bar is integrally joined to a holder body by insert molding, and the bridge portions are severed, thereby separating the bus bar structure from the carrier. Such a production method is disclosed in the Unexamined Japanese Patent Application Publication No. Hei 9-213436.
In the production method disclosed in the above publication, the bus bars of the chain terminal structure are connected to the carrier in such a manner that projected ends of tabs are continuous with the bridge portions. Therefore, when the bridge portions are severed or cut off, cutting marks are formed on the tabs, which leads to a possibility that the distal end of the tab, pressed into a tapering shape, is deformed, and in the case where a flash is kept formed on the tab, there is a possibility that a metal terminal is caught by the flash when connecting the metal terminal to the tab.
This invention has been made under the above circumstances, and an object of the invention is to provide a construction in which any portion of a low strength does not need to be formed on a die.
According to the present invention, there is provided a joint connector comprising a housing having a plurality of juxtaposed metal terminals received therein; and a bus bar structure having a plurality of bus bars each having a plurality of tabs; wherein when the bus bar structure is attached to the housing, the tabs contact the associated metal terminals, respectively, so that the metal terminals are short-circuited in a predetermined pattern; and wherein a bus bar base member, having the plurality of juxtaposed tabs extending from a side edge of an interconnecting portion, is integrally joined to a holder body of a synthetic resin, having a plurality of punching holes, by insert molding, thereby forming the bus bar structure, that portion of the interconnecting portion, disposed between the adjacent tabs, being exposed through the corresponding punching hole; and the interconnecting portion is severed at any one of the plurality of punching holes, thereby dividing the bus bar base member into the plurality of bus bars; CHARACTERIZED in that that surface of the interconnecting portion, facing away from the punching holes, is exposed at those regions, corresponding respectively to the punching holes, and those regions, each disposed between the adjacent punching holes, to an outer surface of the holder body over an entire area thereof.
In the invention, a cap is attached to the housing to cover the bus bar structure.
In the invention, a seal member is provided on the housing, and is fitted watertight in an open end of the cap.
(Aspect 1)
That surface of the interconnecting portion, facing away from the punching holes, is exposed at those regions, corresponding respectively to the punching holes, and those regions, each disposed between the adjacent punching holes, to the outer surface of the holder body over the entire area thereof. Therefore, when there is used a die adapted to be held against this exposed surface, there is no need to form any convex portion of a low strength on the die.
(Aspect 2)
The one side (surface) of the interconnecting portion of the bus bar structure is exposed over the entire area thereof, and any partition portion is not provided between the bus bars separated from each other at the severed portion. Therefore, if a foreign matter is deposited on the two bus bars in a manner to bridge this severed portion, the two bus bars are electrically connected to each other. In the invention, however, the bus bar structure is covered with the cap, and therefore the deposition of such a foreign matter is prevented, thus preventing the two bus bars from being electrically connected together.
(Aspect 3)
When the cap is attached to the housing, the seal member is snugly fitted in the open end of the cap in a watertight manner, thereby preventing the intrusion of water into the cap, thus preventing the water from reaching the bus bar structure.
Further, this invention has been made under the above circumstances, and an object of the invention is to provide a construction in which the alignment of tabs are prevented from being adversely affected by an injection pressure during the insert molding of a bus bar structure.
(Aspect 4)
According to a 4th aspect of the present invention, there is provided a joint connector comprising:
a housing having a plurality of juxtaposed metal terminals received therein; and
a bus bar structure having a plurality of bus bars each having a plurality of tabs;
wherein when the bus bar structure is attached to the housing, the tabs contact the associated metal terminals, respectively, so that the metal terminals are short-circuited in a predetermined pattern;
wherein a bus bar base member, having the plurality of juxtaposed tabs extending from a side edge of an interconnecting portion, is integrally joined to a holder body of a synthetic resin, having a plurality of punching holes, by insert molding, thereby forming the bus bar structure, that portion of the interconnecting portion, disposed between the adjacent tabs, being exposed through the corresponding punching hole; and the interconnecting portion is severed at any one of the plurality of punching holes, thereby dividing the bus bar base member into the plurality of bus bars;
Characterized in that window holes are formed in the holder body, and opposite end portions of the interconnecting portion, disposed outside a severance-applying portion of the interconnecting portion, are exposed to the exterior through the respective window holes.
(Aspect 5)
According to a 5th aspect of the invention, there is provided a method of producing a joint connector comprising:
a housing having a plurality of juxtaposed metal terminals received therein; and
a bus bar structure having a plurality of bus bars each having a plurality of tabs;
wherein when the bus bar structure is attached to the housing, the tabs contact the associated metal terminals, respectively, so that the metal terminals are short-circuited in a predetermined pattern;
wherein a bus bar base member, having the plurality of juxtaposed tabs extending from a side edge of an interconnecting portion, is integrally joined to a holder body of a synthetic resin, having a plurality of punching holes, by insert molding, thereby forming the bus bar structure, that portion of the interconnecting portion, disposed between the adjacent tabs, being exposed through the corresponding punching hole; and the interconnecting portion is severed at any one of the plurality of punching holes, thereby dividing the bus bar base member into the plurality of bus bars;
Characterized in that during the insert molding, opposite end portions of the interconnecting portion, disposed outside a severance-applying region of the interconnecting portion, are held.
(The Invention of Aspect 4)
During the insert molding of the bus bar structure, part of a mold is disposed in spaces, corresponding respectively to the window holes provided respectively at the opposite end portions, to hold the opposite end portions of the interconnecting portion, and therefore the deformation of the opposite end portions of the interconnecting portion by an injection pressure is prevented, and therefore the alignment of the tabs, disposed respectively at the opposite end portions of the interconnecting portion, will not be adversely affected.
(The Invention of Aspect 5)
During the insert molding of the bus bar structure, the mold holds the opposite end portions of the interconnecting portion, and therefore the deformation of the opposite end portions of the interconnecting portion by the injection pressure is prevented, and therefore the alignment of the tabs, disposed respectively at the opposite end portions of the interconnecting portion, will not be adversely affected.
Still further, this invention has been made under the above circumstances, and an object of the invention is to provide a construction in which a cutting mark is prevented from being formed on tabs when cutting a bus bar structure off from a carrier.
(Aspect 6)
According to a 6th aspect of the invention, there is provided a joint connector comprising:
a housing having a plurality of juxtaposed metal terminals provided therein; and
a bus bar structure, which includes an electrically-conductive bus bar, having a plurality of juxtaposed tabs extending from an edge of an interconnecting portion, and a holder body of a synthetic resin integrally joined to the bus bar;
wherein when the bus bar structure is attached to the housing, the tabs contact the associated metal terminals, respectively, so that the metal terminals are short-circuited in a predetermined pattern;
wherein there is provided a chain terminal structure having a plurality of the bus bars connected to side edges of a carrier through bridge portions, and the bus bar of the chain terminal structure is integrally joined to the holder body by insert molding, and the bus bar and the holder body, thus integrally joined together, are separated from the carrier by cutting the bridge portions;
Characterized in that each of the bus bars of the chain terminal structure is connected to the carrier through the bridge portions connected to the interconnecting portion of the bus bar.
(Aspect 7)
In a 7th aspect of the invention, the bus bar of the chain terminal structure is connected to the carrier through the bridge portions connected to that edge of the interconnecting portion facing away from the tabs, and cut surfaces of the bridge portions of the bus bar structure are exposed to an outer surface of the holder body, and the bus bar structure is attached to the housing by pushing the outer surface, to which the cut surfaces of the bridge portions are exposed, by the finger; and recesses are formed respectively in those portions of the outer surface of the holder body to which the cut surfaces of the bridge portions are exposed, respectively, and each of the bridge portions is cut at a portion thereof disposed immediately adjacent to a bottom surface of the corresponding recess.
(Aspect 8)
According to an 8th aspect of the invention, there is provided a method of producing a joint connector comprising:
a housing having a plurality of juxtaposed metal terminals provided therein; and
a bus bar structure, which includes an electrically-conductive bus bar, having a plurality of juxtaposed tabs extending from an edge of an interconnecting portion, and a holder body of a synthetic resin integrally joined to the bus bar;
wherein when the bus bar structure is attached to the housing, the tabs contact the associated metal terminals, respectively, so that the metal terminals are short-circuited in a predetermined pattern; Characterized by the steps of:
forming, by pressing, a chain terminal structure having a plurality of the bus bars connected to side edges of a carrier through bridge portions, the bridge portions being connected to the edge of the interconnecting portion of the bus bar;
integrally joining the bus bar to the holder body by insert molding; and
separating the bus bar and the holder body, thus integrally joined together, from the carrier by cutting the bridge portions, thereby obtaining the bus bar structure.
(The Inventions of Aspects 6 and 8)
Each bus bar of the chain terminal structure is connected to the carrier not through the tabs but via the side edge of the interconnecting portion. Therefore, when the bridge portions are cut or severed, any cutting mark is not formed on the tabs.
(The Invention of Aspect 7)
When attaching the bus bar structure to the housing, the outer surface of the holder body, facing away from the tabs (that is, that surface to which the cut surfaces of the bridge portions are exposed), is pushed by the finger. The cut surface of each bridge portion is disposed inwardly of the outer surface of the holder body, and therefore the finger will not come into contact with the cut surface of the bridge portion.